CWG3007 Access check for synthesized comparison operators

[jensmaurer]

Consider:

 struct Base {
   protected:
     bool operator==(const Base& other) const = default;
   };

   struct Child : Base {
     int i;
     bool operator==(const Child& other) const = default;
   };

   bool b = Child() == Child(); // error: deleted operator== because Base::operator== is inaccessible

CWG asks EWG to determine whether the access check for Base::operator== in the protected base class should succeed when synthesizing Child::operator==. In the status quo, the access check fails because the relevant object expression is actually of type Base.

See CWG3007 for details.

[erichkeane]

EWG discussed this during the Monday AM session in Sofia.

The room decided with UNANIMOUS CONSENT that the access check for Base::operator== should succeed when synthesizing the Child::operator==.